Palace went into the break three goals to the good and came out racing in the second-half in search of more, but early momentum was with the hosts as they were awarded a penalty.
David Smith stepped up from 12-yards for Cray Wanderers, but he smashed the crossbar and the rebound was put well over.
On the hour-mark, Seb Williams added a fourth for Palace following some sublime footwork inside the box. He held off a challenge, took it to the byline and managed to sneak it past the ‘keeper from the tightest of angles.
With a quarter of an hour remaining, Matteo Dashi curled home a fifth to all but seal the win for Palace. He found himself in space on the edge of the box and curled in a peach of an effort on his left foot.
A sixth looked on the cards for Palace in the time that remained, though Redhead saw a header glance wide of the far post and Cowin’s dinked effort just went narrowly over the crossbar.
With what was effectively the last kick of the game, Williams netted his second with a long-range effort. Cray’s goalkeeper got a hand to it, but it was hit low and hard into the bottom corner.
A solid display from Rob Quinn’s young Eagles, as they prepare for their new campaigns in the U18 Premier League South, the FA Youth Cup and the U18 Premier League Cup.
Cray: Trialist (GK), Taylor, Ijaha, Bonner, Trialist, Edwards, Trialist, Trialist, Clunis, Smith.
Palace: Hill (GK) (Khoshaba (GK), 61), Whyte, King (Muwana, HT), Somade, Walker-Smith, Cowin, Williams, Adams-Collman, Dashi, Lameiras, Redhead.
Subs: Judd, Osei, Montjen, Danaher, Casey.